blob: 4d3e9c7b7c5729d300be12e9fdf241ae63643e16 [file] [log] [blame]
Robert Love42e9a922008-12-09 15:10:17 -08001/*
2 * Copyright(c) 2007 Intel Corporation. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
16 *
17 * Maintained at www.Open-FCoE.org
18 */
19
20#ifndef _FC_FRAME_H_
21#define _FC_FRAME_H_
22
23#include <linux/scatterlist.h>
24#include <linux/skbuff.h>
25#include <scsi/scsi_cmnd.h>
26
27#include <scsi/fc/fc_fs.h>
28#include <scsi/fc/fc_fcp.h>
29#include <scsi/fc/fc_encaps.h>
30
Chris Leech11b56182009-11-03 11:46:29 -080031#include <linux/if_ether.h>
32
Robert Love42e9a922008-12-09 15:10:17 -080033/*
34 * The fc_frame interface is used to pass frame data between functions.
35 * The frame includes the data buffer, length, and SOF / EOF delimiter types.
36 * A pointer to the port structure of the receiving port is also includeded.
37 */
38
39#define FC_FRAME_HEADROOM 32 /* headroom for VLAN + FCoE headers */
40#define FC_FRAME_TAILROOM 8 /* trailer space for FCoE */
41
Yi Zoud37322a2009-10-21 16:27:58 -070042/* Max number of skb frags allowed, reserving one for fcoe_crc_eof page */
43#define FC_FRAME_SG_LEN (MAX_SKB_FRAGS - 1)
44
Robert Love42e9a922008-12-09 15:10:17 -080045#define fp_skb(fp) (&((fp)->skb))
46#define fr_hdr(fp) ((fp)->skb.data)
47#define fr_len(fp) ((fp)->skb.len)
48#define fr_cb(fp) ((struct fcoe_rcv_info *)&((fp)->skb.cb[0]))
49#define fr_dev(fp) (fr_cb(fp)->fr_dev)
50#define fr_seq(fp) (fr_cb(fp)->fr_seq)
51#define fr_sof(fp) (fr_cb(fp)->fr_sof)
52#define fr_eof(fp) (fr_cb(fp)->fr_eof)
53#define fr_flags(fp) (fr_cb(fp)->fr_flags)
54#define fr_max_payload(fp) (fr_cb(fp)->fr_max_payload)
Yi Zoub277d2a2009-02-27 14:07:21 -080055#define fr_fsp(fp) (fr_cb(fp)->fr_fsp)
Robert Love42e9a922008-12-09 15:10:17 -080056#define fr_crc(fp) (fr_cb(fp)->fr_crc)
57
58struct fc_frame {
59 struct sk_buff skb;
60};
61
62struct fcoe_rcv_info {
63 struct packet_type *ptype;
64 struct fc_lport *fr_dev; /* transport layer private pointer */
65 struct fc_seq *fr_seq; /* for use with exchange manager */
Yi Zoub277d2a2009-02-27 14:07:21 -080066 struct fc_fcp_pkt *fr_fsp; /* for the corresponding fcp I/O */
Robert Love42e9a922008-12-09 15:10:17 -080067 u32 fr_crc;
68 u16 fr_max_payload; /* max FC payload */
69 enum fc_sof fr_sof; /* start of frame delimiter */
70 enum fc_eof fr_eof; /* end of frame delimiter */
71 u8 fr_flags; /* flags - see below */
Chris Leech11b56182009-11-03 11:46:29 -080072 u8 granted_mac[ETH_ALEN]; /* FCoE MAC address */
Robert Love42e9a922008-12-09 15:10:17 -080073};
74
75
76/*
77 * Get fc_frame pointer for an skb that's already been imported.
78 */
79static inline struct fcoe_rcv_info *fcoe_dev_from_skb(const struct sk_buff *skb)
80{
81 BUILD_BUG_ON(sizeof(struct fcoe_rcv_info) > sizeof(skb->cb));
82 return (struct fcoe_rcv_info *) skb->cb;
83}
84
85/*
86 * fr_flags.
87 */
88#define FCPHF_CRC_UNCHECKED 0x01 /* CRC not computed, still appended */
89
90/*
91 * Initialize a frame.
92 * We don't do a complete memset here for performance reasons.
93 * The caller must set fr_free, fr_hdr, fr_len, fr_sof, and fr_eof eventually.
94 */
95static inline void fc_frame_init(struct fc_frame *fp)
96{
97 fr_dev(fp) = NULL;
98 fr_seq(fp) = NULL;
99 fr_flags(fp) = 0;
100}
101
102struct fc_frame *fc_frame_alloc_fill(struct fc_lport *, size_t payload_len);
Vasu Deva7bbc7f2009-11-03 11:47:55 -0800103struct fc_frame *_fc_frame_alloc(size_t payload_len);
Robert Love42e9a922008-12-09 15:10:17 -0800104
105/*
106 * Allocate fc_frame structure and buffer. Set the initial length to
107 * payload_size + sizeof (struct fc_frame_header).
108 */
109static inline struct fc_frame *fc_frame_alloc(struct fc_lport *dev, size_t len)
110{
111 struct fc_frame *fp;
112
113 /*
114 * Note: Since len will often be a constant multiple of 4,
115 * this check will usually be evaluated and eliminated at compile time.
116 */
Vasu Deva7bbc7f2009-11-03 11:47:55 -0800117 if (len && len % 4)
Robert Love42e9a922008-12-09 15:10:17 -0800118 fp = fc_frame_alloc_fill(dev, len);
119 else
Vasu Deva7bbc7f2009-11-03 11:47:55 -0800120 fp = _fc_frame_alloc(len);
Robert Love42e9a922008-12-09 15:10:17 -0800121 return fp;
122}
123
124/*
125 * Free the fc_frame structure and buffer.
126 */
127static inline void fc_frame_free(struct fc_frame *fp)
128{
129 kfree_skb(fp_skb(fp));
130}
131
132static inline int fc_frame_is_linear(struct fc_frame *fp)
133{
134 return !skb_is_nonlinear(fp_skb(fp));
135}
136
137/*
138 * Get frame header from message in fc_frame structure.
139 * This hides a cast and provides a place to add some checking.
140 */
141static inline
142struct fc_frame_header *fc_frame_header_get(const struct fc_frame *fp)
143{
144 WARN_ON(fr_len(fp) < sizeof(struct fc_frame_header));
145 return (struct fc_frame_header *) fr_hdr(fp);
146}
147
148/*
149 * Get frame payload from message in fc_frame structure.
150 * This hides a cast and provides a place to add some checking.
151 * The len parameter is the minimum length for the payload portion.
152 * Returns NULL if the frame is too short.
153 *
154 * This assumes the interesting part of the payload is in the first part
155 * of the buffer for received data. This may not be appropriate to use for
156 * buffers being transmitted.
157 */
158static inline void *fc_frame_payload_get(const struct fc_frame *fp,
159 size_t len)
160{
161 void *pp = NULL;
162
163 if (fr_len(fp) >= sizeof(struct fc_frame_header) + len)
164 pp = fc_frame_header_get(fp) + 1;
165 return pp;
166}
167
168/*
169 * Get frame payload opcode (first byte) from message in fc_frame structure.
170 * This hides a cast and provides a place to add some checking. Return 0
171 * if the frame has no payload.
172 */
173static inline u8 fc_frame_payload_op(const struct fc_frame *fp)
174{
175 u8 *cp;
176
177 cp = fc_frame_payload_get(fp, sizeof(u8));
178 if (!cp)
179 return 0;
180 return *cp;
181
182}
183
184/*
185 * Get FC class from frame.
186 */
187static inline enum fc_class fc_frame_class(const struct fc_frame *fp)
188{
189 return fc_sof_class(fr_sof(fp));
190}
191
192/*
193 * Check the CRC in a frame.
194 * The CRC immediately follows the last data item *AFTER* the length.
195 * The return value is zero if the CRC matches.
196 */
197u32 fc_frame_crc_check(struct fc_frame *);
198
199static inline u8 fc_frame_rctl(const struct fc_frame *fp)
200{
201 return fc_frame_header_get(fp)->fh_r_ctl;
202}
203
204static inline bool fc_frame_is_cmd(const struct fc_frame *fp)
205{
206 return fc_frame_rctl(fp) == FC_RCTL_DD_UNSOL_CMD;
207}
208
Robert Love42e9a922008-12-09 15:10:17 -0800209/*
210 * Check for leaks.
211 * Print the frame header of any currently allocated frame, assuming there
212 * should be none at this point.
213 */
214void fc_frame_leak_check(void);
215
216#endif /* _FC_FRAME_H_ */